Abstract: A centrifugal fan arrangement includes a centrifugal fan rotatably mounted within a scroll housing and a plurality of circumferentially spaced fan blades fixed to a central fan axle extending along an axial direction and/or to a circumferential fan ring extending in a plane orthogonal to an axial direction. The scroll housing includes a housing main portion with a maximum housing diameter D and a maximum axial housing width H, a housing inlet portion and a housing outlet portion, said housing main portion surrounding said centrifugal fan at radially outer locations to define a circumferentially extending air guiding space. The housing inlet portion is located at radially inner locations to define an inner air inlet space. The housing outlet portion is located at a radially outer location to define an air outlet space.

Abstract: A heat recovery unit with a unit housing (11) defining a unit compartment, a heat exchanger (20), a fresh air bypass flow passage and/or an exhaust air bypass flow passage, a fresh air centrifugal fan arrangement (41) and an exhaust air centrifugal fan arrangement (42), a fresh air filter (51) and an exhaust air filter (52).

Abstract: The invention relates to an air filter assembly (1) for a heat recovery ventilation unit. The air filter assembly comprises a frame (2) and a filtering element (3) fixed within said frame (2). The frame (2) comprises a first frame portion (2a) having a first height; a second frame portion (2b) opposite said first frame portion (2a) and having a second height; a third frame portion (2c); and a fourth frame portion (2d) opposite said third frame portion (2c). The third and fourth frame portions (2c, 2d) each extend between said first and second frame portions (2a, 2b). The second height is greater than the first height of said first frame portion. A height of said third frame portion (2c) is comprised between said first and second heights; and a height of said fourth frame portion (2d) is comprised between said first and second heights.

Abstract: The invention relates to an air diffuser device (1) for ventilating rooms and to be installed in a ventilation duct opening in a wall or ceiling of a room, said air diffuser device (1) comprising a baffle element (10) having a central region (10a) and a peripheral region (10b) with a peripheral edge (12; 13) for deviating at least a part of a ventilation air flow entering said room through said ventilation duct opening in a flow direction with an air flow component parallel to said wall or ceiling. The baffle element (10) comprises a plurality of slits or grooves (11) each extending from the central region (10a) of said baffle element (10) to the peripheral region (10b) of said baffle element (10). In addition, the peripheral edge (13) of said baffle element (10) has a plurality of radially extending indentations (14) spaced from each other along the periphery of said baffle element (10).

Abstract: The invention relates to a heat exchanger block 2 and to a heat recovery ventilation unit 1 comprising such a heat exchanger block. In the heat exchanger block 2, the individual flow cross-section (Q1) of flow passages of said plurality of first air flow passages (AFP1) in said parallel flow region (PF) and the individual flow cross-section (Q2) of flow passages of said plurality of second air flow passages (AFP2) in said parallel flow region (PF) gradually, preferably linearly, decrease along a straight line (x-x) perpendicular to the parallel air flow passages (AFP1 and AFP2) and from said first wall (W1) to said second wall (W2) of the block.

Abstract: The invention relates to a heat exchanger block 2 and to a heat recovery ventilation unit 1 comprising such a heat exchanger block. In the heat exchanger block 2, the individual flow cross-section (Q1) of flow passages of said plurality of first air flow passages (AFP1) in said parallel flow region (PF) and the individual flow cross-section (Q2) of flow passages of said plurality of second air flow passages (AFP2) in said parallel flow region (PF) gradually, preferably linearly, decrease along a straight line (x-perpendicular to the parallel air flow passages (AFP1 and AFP2) and from said first wall (W1) to said second wall (W2) of the block.